That is possible to do, but do you want to copy the settings from one model on your taranis to another, or the settings from one pixhawk to another?

In the case of copying pixhawk parameters to another pixhawk, that is possible assuming you are using the same platform, IE one quadcopter to another quadcopter. However if copying from a quadcopter to a hexacopter, you can still copy some of the settings but not all of them.

The way this works on mission planner, you just need to go the the configuration> advanced-parameter-list and on the right you will see the option to save and load parameters from file on your PC.